GHSA-35RM-7J9C-2F7M async-tar PAX extension-header desync enables tar entry/content smuggling

Summary async-tar v0.6.0 mis-applies a buffered PAX size extension to an intermediary extension header a GNU longname L, a GNU longlink K, or a PAX x/g header instead of to the next file entry. POSIX requires a PAX extended-header record set to describe the next file entry, never an intervening...